A5043955820- Mass Spectrometry Techniques and Applications
- Analytical Chemistry and Chromatography
- Ion-surface interactions and analysis
- Energetic Materials and Combustion
- Analytical chemistry methods development
- Bacterial Identification and Susceptibility Testing
- Forensic Fingerprint Detection Methods
- Advanced Proteomics Techniques and Applications
- Antibiotic Resistance in Bacteria
- Thermal and Kinetic Analysis
- Metabolomics and Mass Spectrometry Studies
- Chemical Reaction Mechanisms
- Glycosylation and Glycoproteins Research
- Electrohydrodynamics and Fluid Dynamics
- Genomics and Phylogenetic Studies
- Advanced Chemical Sensor Technologies
United States Department of Homeland Security
2024
Eastern Regional Research Center
2018
Agricultural Research Service
2018
Temple University
2012-2016
Photonics (United States)
2012-2016
A direct, sensitive, and rapid method for the detection of smokeless powder components, from five different types ammunition, is demonstrated using laser electrospray mass spectrometry (LEMS). Common components found in powder, such as ethyl centralite, methyl dibutyl phthalate, dimethyl are detected under atmospheric conditions without additional sample preparation. LEMS analysis powders revealed several new spectral features that have not been identified previously. Offline principal...
The internal energy distributions for dried and liquid samples that were vaporized with femtosecond duration laser pulses centered at 800 nm postionized by electrospray ionization-mass spectrometry (LEMS) measured compared conventional ionization mass (ESI-MS). energies of the spectral techniques determined plotting ratio intact parent molecular features to all integrated ion intensities fragments as a function collisional using benzylpyridinium salts peptides. Measurements p-substituted...
Quantitative measurements of atenolol, tioconazole, tetraethylammonium bromide, and tetrabutylammonium iodide using laser electrospray mass spectrometry (LEMS) reveal monotonic signal response as a function concentration for single analytes, two- four-component equimolar mixtures, two-component variable molarity mixtures. LEMS analyses analytes were linear over ~2.5 orders magnitude all four displayed no sign saturation. Corresponding ionization (ESI) nonmonotonic increase saturation...
A comparison of the mass spectral response for myoglobin, cytochrome c, and lysozyme is presented laser electrospray spectrometry (LEMS) ionization-mass (ESI-MS). Analysis multicomponent protein solutions using nonresonant femtosecond (fs) vaporization with postionization exhibited significantly reduced ion suppression effects in conventional ESI analysis, enabling quantitative measurements over 4 orders magnitude concentration. No significant charge reduction was observed LEMS experiment...
Rationale The occurrence of antibiotic‐resistant bacteria is a worldwide issue that has the potential, if not addressed, to eliminate classes antibiotics have extended life expectancy in last century. An approach confront this threat development technologies greatly accelerate detection antibiotic resistance minimize unnecessary treatment involving antibiotics. Development an analytical method for rapid aminoglycoside using liquid chromatography/mass spectrometry (LC/MS) been reported...
Resolution and sensitivity improvements in mass spectrometry technology have enabled renewed attempts at solving challenging analytical issues. One such issue involves the analysis of energetic ionic species. Energetic species make up an important class chemical materials, a more robust versatile platform would provide tremendous value to community. Initial quantification employed high-resolution time-of-flight measurements with crown ether (CE) complexation flow injection (FIA). In this...
Femtosecond (fs) laser vaporization is used to transfer cytochrome c, myoglobin, lysozyme, and ubiquitin from the condensed phase into an electrospray (ES) plume consisting of a mixture supercharging reagent, m-nitrobenzyl alcohol (m-NBA), trifluoroacetic acid (TFA), acetic (AA), or formic (FA). Interaction acid-sensitive proteins like c myoglobin with highly charged ES droplets resulted in shift higher charge states comparison acid-stable lysozyme ubiquitin. Laser mass spectrometry (LEMS)...
Nonresonant laser vaporization combined with high-resolution electrospray time-of-flight mass spectrometry enables analysis of a casing after discharge firearm revealing organic signature molecules including methyl centralite (MC), diphenylamine (DPA), N-nitrosodiphenylamine (N-NO-DPA), 4-nitrodiphenylamine (4-NDPA), DPA adduct, and multiple unidentified features not observed in previous spectral measurements. Collision-induced dissociation measurements unknown GSR ions reveals inorganic...
Worldwide efforts are underway to determine the extent of antimicrobial resistance (AMR). In 2015, World Health Organization (WHO) founded Global Antimicrobial Surveillance System (GLASS) focusing on surveillance and dissemination data. addition, WHO advocates method development focused rapid determination close real-time monitoring antibiotic usage its effectiveness. Rapid aminoglycoside modification by O-phosphorylation, most prevalent mechanism clinical resistance, was performed using...
Nitro- and inorganic-based energetic material is vaporized at atmospheric pressure using nonresonant, 70 femtosecond laser pulses prior to electrospray post-ionization transfer into a time-of-flight mass spectrometer for analysis. Measurements of nitro-based molecule, cyclotrimethylenetrinitramine (RDX), adsorbed on metal dielectric surfaces indicate nonresonant vaporization intact molecules, demonstrating the universality spectrometry (LEMS) technique explosives. In addition, RDX analyzed...
Abstract 1,3,5‐trinitroso‐1,3,5‐triazine (R‐Salt) is an insensitive energetic that has previously been used as improvised explosive. The work presented here a comprehensive study on the thermal properties and chemical characterization of R‐Salt. Thermal analysis was performed via differential scanning calorimetry (DSC) thermogravimetric (TGA) which found both crude recrystallized R‐Salt have similar but selected lid impacted profile onset temperature. Chemical Raman, Fourier‐transform...